Drain cover for generally open flat drainage areas with debris blockage and open drainage portions

ABSTRACT

A drain cover having a main drainage surface with relatively larger apertures or openings therein, comprising generally 50 percent of the surface, so that larger debris is accepted into a related drain pipe when a depending skirt portion of the drain cover, having smaller perforations, becomes clogged. In this way a two-layer drainage system for a generally flat surface is provided that allows draining of water and small particulates alone when possible, but upon the clogging of the smaller openings the generally flat surface can be protected from flooding by allowing larger particulates to drain into the main drainage surface. The main drainage surface is held above the flat surface by the depending skirt, at a level of 3/8 to 1 inch above the flat surface. When the depending skirt openings are clogged the water and debris will rise until allowed to drain into the larger openings of the main drainage surface.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/614,043; filed on Sep. 13, 2012, and now pending, the fulldisclosures of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention concerns a drain cover for use on drainage pipesthat are within generally open flat surfaces prone to flooding. Moreparticularly the present invention concerns a drain cover having agenerally flat surface, open to a drainage pipe and a skirt dependingfrom the flat surface for drainage of water even in the presence ofdebris that otherwise would block the drain. The skirt and flat surfaceportions of the drain cover each overlying the surface to be drained ina manner that permits drainage while preventing flooding due to theblockage of drain holes. The device in a preferred embodiment is usedoutside of a walk-out basement or another entry door that is close toor, below grade and as such is prone to flooding. Further, the devicecan also be adapted for use within drains in window-wells.

BACKGROUND OF THE INVENTION

Presently there are drain covers for use on driveways, patios, walk-outbasement doors below grade, interior spaces, window wells and other dryland flat surfaces that are subject to flooding. Most such drain covershave a generally circular planar shape with either holes or slotstherein to permit water to drain there through while preventing debrisfrom entering the drainage pipe and water removal systems. Such drainsare typically connected, via pipes, to storm sewer or other waterremoval systems. While it is desirable to remove water alone from suchsurfaces, often times the surfaces will have leaves, grass, soil andother debris thereon. Municipalities typically are desirous that onlywater be permitted through to storm sewer systems; in order toaccomplish this, the drain covers are typically generally solid withsmall perforations thereon to allow water, and only tiny particles ofdebris, to enter and proceed to the storm sewer.

In certain situations, municipalities must make some allowance for theentry of debris into water removal systems, or risk dangerous flooding.For example, on road surfaces, the presence of water can result indangerous hydroplaning and other flooding conditions causing safetyhazards. For those situations culvert drainage systems have beendeveloped wherein a drain is placed against an elevated curb, with apartially open top surface and a depending perforated skirt. However,these types of drains are only possible against curbs as the skirtportion is typically quite elevated (so as to be effective only duringperiods of high water) and would prove a high obstacle on a flatsurface. Patents covering these types of culvert systems and systems fortreating water runoff from such, include U.S. Pat. Nos. 7,534,355,Lockerman et al. Storm Drain Filter With Variable Flow Capacity; and8,017,004, Crumpler, Storm Drain and Filter System; and 7,332,091,Peters, Jr. et al., Process for Treating Storm Water. Each of theseshows variable sized openings but are of a type that can only be used inthe side of the curb on a roadway, due to their large size and shape andwhich could not be adopted for flat surface use.

However, in areas of generally open flat areas, such as patios anddriveways that are in proximity to a house or other structure, the useof drains that have small holes or slots so as to permit drainage ofwater alone, often cause flooding situations when the small holes orslots become blocked by debris. This flooding has deleterious effects onthe nearby house or structure and/or other property, causing damagesthat are often measured in the thousands of dollars. The allowance ofleaves or other debris into storm sewers or other drainage systems canbe otherwise managed and would cause less damage than that otherwisesuffered. For example, U.S. Patent Application Publication No.2005/0247612, Glassheim, Silt and Debris Filtering System for StormDrains, tries to solve the problem by capturing the large debris withina drain, but there is a requirement for the user to occasionally comeand clear out the debris trap, and in the interim flooding can occur.Further, the device shown is more appropriate for use at curbside orwithin a storm sewer system, as the device is placed at the opening ofthe drain within the storm sewer and likely would not fit within asmaller drain used on a flat surface. U.S. Pat. No. 6,793,811,Fleischmann, Runoff Drain Filter with Separately Removable Cartridges,shows a more modern approach to run off filters, but suffers the sameissues and is also not appropriate to flat surface drainage. Further,the height of drains used on flat surfaces, particularly those whereautomobile or pedestrian traffic is common, must be low profile so thatthe drain covers do not prove an impediment or hazard to automobiles orpedestrians traversing the flat surface.

It would be desirable to have a drain cover that would block debris fromentering a swim sewer system until the threat of flooding occurs andthereafter concomitantly permit drainage of large debris until thethreat is alleviated.

In the past, some surface drains have been made of a type having smallopenings to permit water and small debris to enter and which aretypically mounted such that the top surface of the drain cover is flushwith the surface to be drained. For example, U.S. Pat. No. 4,655,913,Boersma, Adjustable Drain Cove and Design U.S. Pat. No. 256,948,Boersman, Drain Cover, presents drains wherein small holes are providedfor drainage, the device including means to adjust the fit of the coverwithin the pipe from outside of the cover. However, the '913 and '948patents suffer the problem that when debris is brought towards thedrain, with the natural flow of water, these drains will likely beclogged allowing the surface to flood. In U.S. Pat. Nos. 134,978, Clapp,Gratings for Sewer Inlet; 5,724,684, Paar, Raised Strainer; 7,300,573,Trangsrud, Catch Basin Filter; D606,174, Martin, Debris Cage; and Des.388,725, Trampush, Strainer for Downspouts, various types of surfacestrainers are provided each having either an elevated portion very highabove the surface, or offering only minimal allowance for the removal oflarge debris. The height of the devices claimed and shown in thesepatents makes them unsuitable for flat surfaces where pedestrians willwalk or vehicles will traverse, as the devices will prove an impedimentto safe travel.

In addition there are some drains made for the bottoms of pools that arealso of a type having an elevation from a flat surface, such as thatshown in U.S. Pat. No. 6,588,029, Mullings, Safety Drain Guard forSwimming Pools and Spas and U.S. Pat. No. 6,393,631, Schroader, DrainSafety Cover System and Method, and while larger openings are shown incombination with smaller openings, these drains are designed to cleanthe pool and not to drain a flat surface that is suppose to remain dry.Such systems are further designed to prevent persons from being trappedby suction on a pool drain and thus provide different levels of waterintake so that vacuum created by suction can be broken more easily.Further, the designs have a similar flaw in that they are raised abovethe surface such that the use of such drains on flat dry surfaces wouldprove a hazard to travel; their placement in a swimming pool,particularly in the deep end, causes no such hazard.

Objects and advantages of the present invention will become apparent asthe description proceeds.

SUMMARY OF THE INVENTION

In accordance with the present invention, a drain cover, for use on adrain opening in a generally flat surface is provided. The drain coverincludes a plate having an aperture or opening thereon to permit wateror other fluids to flow therethrough. The aperture encompasses a desiredamount of area of the surface of the plate, such that sufficient watercan flow therein to avoid flooding of the flat surface. The plate in apreferred embodiment has an edge about its perimeter and a skirt isattached to the edge of the plate and depends therefrom, the skirthaving a lower edge for placement adjacent the generally flat surfaceand perforations therethrough to permit the flow of liquids. The draincover can be positioned in a drain pipe on a surface to accept fluidthrough the plate aperture only when the perforations of its skirt areblocked and water rises above the skirt.

In one embodiment, the drain cover and aperture are of a sufficient sizeto accept large leaves through the aperture. The preferred embodiment ofthe drain cover of the present invention has a skirt length of between3/8 inch and 1 inch; however as needed other sizes can be used.Preferred skirt heights of ½ inch and ¾ inch are envisioned for manysituations. In a preferred embodiment the plate comprises a circulararea and the skirt depends from the circumference thereof

In one embodiment, the top of the device is generally open having an “X”shaped structural element spanning across diameters of the plate;thereby providing the largest apertures possible while also providingstructural support for the drain cover and any large objects place ortraversing thereon. The “X” shape of the element is such so as toprovide great strength with as little material as possible to therebyhave the largest openings for water. The structural element allows thedevice to be light weight, open to significant water flow and allows thedevice to be traversed by something as weighty as a person or a vehicleon a driveway. It will be understood that the “X” shape also preventslarger object, such as balls or children's toys or the like, from beingbrought into the drain or from jamming or blocking the drain.

The drain cover includes at least one leg, attached to the plate,depending therefrom for insertion into a drain pipe. Further, the atleast one leg comprises a friction element for placement against theinterior wall of a drain pipe allowing removable contact of the coverwith the drain pipe. In a preferred embodiment the drain cover has fourlegs, at about 90 degrees from each other, with each having a frictionelement thereon.

In one embodiment, the drain cover further comprising a shutter systemto close off the aperture(s) or opening(s); the shutter system can beoperated manually or with sensors, microprocessors, motors and softwareor other elements, that can determine when opening and closing of theshutters is needed and to what extent for each drainage situation. Theshutters of the present embodiment are movable within the device so asto adjust the size of the aperture while the drain cover is in place inthe pipe.

In another embodiment of the present invention a drain cover having agenerally cylindrical plate with an aperture or apertures thereon isprovided. The aperture, or opening, covers an area of the platecomprising more than 50% of the surface of the plate so as to allow alarge opening for water and debris to flow through. The plate of thepresent embodiment has an edge about its circumference and includes aperforated skirt depending from the circumference of the plate. Theskirt has a lower edge for placement of the device adjacent the drainagesurface so that the generally cylindrical plate is positioned to acceptfluid through both the skirt openings and aperture only when theperforations of the skirt are either clogged or are otherwiseinsufficient to drain water, and water rises above the skirt. The draincover of this embodiment has four legs with friction fit elements so asto help hold the device within a drainage pipe on a generally flatsurface. The device of the present embodiment may also have a shutter orshutters to close the apertures or openings wherein in a preferredembodiment the shutters are rotatable, relative to the center of theplate, so as to adjust the effective size of the aperture. The preferredembodiment of this drain cover includes means to determine the optimalaperture opening and to adjust the aperture accordingly. Additionallythe shutters may be made with perforations, akin to those on the skirt,such that when the shutters are closed the device provides additionaldrainage even when closed.

A more detailed explanation of the invention is provided in thefollowing description and claims and is illustrated in the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a drain cover of the present invention;

FIG. 2 is a plan view of the top of the drain cover of FIG. 1;

FIG. 3 is an elevational view of a side of the drain cover of FIG. 1;

FIG. 4 is perspective view of another embodiment of the drain cover ofthe present invention in situ on a flat surface;

FIG. 5 is a perspective view of the drain cover of FIG. 1 in situ on aflat surface;

FIG. 6 is a cross-sectional view of a drain cover of the presentinvention in situ;

FIG. 7 is a cut-away perspective view of a drain cover of the presentinvention in situ;

FIG. 8 (A-C) are plan views of the underside of another embodiment ofthe drain cover of FIG. 4;

FIG. 9 is a plan view of another embodiment of the drain cover of FIG.1;

FIG. 10 is a perspective view of the drain cover of FIG. 4; and

FIG. 11 is a perspective view of the drain cover of FIG. 8 (A-C).

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings a number of presently preferredembodiments that are discussed in greater detail hereafter. It should beunderstood that the present disclosure is to be considered as anexemplification of the present invention, and is not intended to limitthe invention to the specific embodiments illustrated. It should befurther understood that the title of this section of this application(“Detailed Description of an Illustrative Embodiment”) relates to arequirement of the United States Patent Office, and should not be foundto limit the subject matter disclosed herein.

Referring now to the drawings, it will be seen that FIGS. 1, 2 and 3show a drain cover 10 of the present invention. It will be seen thatdrain cover 10 comprises a top surface 12 having a rim 14 and crossmember supports 16. It will be understood that the top surface 12 can beconfigured in various manners, as will be shown in further figures anddescribed herein, but that for the operation of the present invention amajority of the top surface will be generally large aperture or opening17 allowing for the flow of liquid and solid matter into a drain that iscovered by the present invention.

It will be seen that drain cover 10 further comprises a depending skirtportion 18 having generally smaller openings 20 therein. Openings 20 aresized to allow fluid to drain therethrough but to block the flow ofdebris (as illustrated in FIGS. 6, 7 and 8) from entering the drain andflowing therethrough. It will be seen that the drain cover 10 of thepresent invention provides, therefore, an area for flow of fluids with ameans to block debris and an area for flow of fluids with means to allowfluid to flow even if mixed with debris, as will be explained below.

In a preferred embodiment, drain cover 10 is formed of a structural-typesteel, known to persons having skill in the art, such that the device isdurable and will withstand the weight of objects, such as vehicles,traversing it as it sits on a flat surface. As the device is subjectedto water and weather conditions, the preferred embodiment is constructedto withstand such, as well as the deleterious effects that weather hason objects. Persons having ordinary skill in the art will understandthat the device can be constructed of any manner of material having theabove noted characteristics, including, but not limited to steel, iron,aluminum, fiberglass, composites and other materials having durabilityand structural strength, without departing from the novel scope of thepresent invention.

Referring again to FIG. 1 drain cover 10 further includes depending legs22 each having a friction element 24 extending therefrom. It will beseen that legs 22 are inset from the rim 14 of drain cover 10 in amanner that permits the legs 22 and friction elements 24 to fit intostandard pipe internal diameters and, via friction elements 24, pressagainst the interior diameter of a pipe so as to hold the drain cover inplace in the pipe and with a bottom rim 26 of drain cover 10, restingagainst the surface 30 (FIGS. 4, 5, 6 and 7) of the surface to bedrained.

Referring now to FIG. 4, a generally flat surface 30, here shown as adriveway of a residence, is shown having a drain pipe 32 located on theflat surface 30. It will be seen that in this example, the flat surface30 is a driveway in front of a garage door 34 (providing access to agarage structure and house or business, not shown). As illustrated,drain cover 110, is a variation of the device shown in FIG. 1, having amore solid upper surface area 112 extending radially in from the rim114. Drain cover 110 can be more clearly viewed in FIG. 10. While draincover 110 is shown and described here, and in FIG. 10, it will beunderstood that a drain cover 10, as shown in FIG. 1, could besubstituted without departing from the novel scope of the presentinvention; such a configuration is illustrated in FIG. 5. It will beseen that drain cover 110 has elements similar to those shown for draincover 10 in FIG. 5, with a similar numbering system for ease ofunderstanding.

Referring to FIG. 5, for more clarity, drain cover 10 is seated onsurface 30, with legs 22 within pipe 32 such that skirt 18 is seated onsurface 30 at bottom rim 26. While bottom rim 26 is not sealed againstsurface 30, in the ordinary use of the present invention, it will beunderstood that such a union permits the flow of fluid under rim 26 butthat debris, smaller than that permitted through opening 20 would likelybe blocked at the described surface of contact. In other situations,persons having ordinary skill in the art will see that drain cover 10can be sealed to surface 30 without departing from the novel scope ofthe present invention, if desired. In the illustrative configuration, itwill be seen that skirt 18 rises above the surface 30 to a desirableheight; in the preferred embodiment the height of skirt 18 isapproximately ¾ inch. It will be understood that skirt 18, duringperiods of normal rain fall and small amounts of surface water,sufficiently permits water to drain through openings 20. Top surface 12,resting on skirt 18 and being above the flow of water in theseconditions is not utilized and any debris on surface 30, which is causedto flow with the water, is trapped by openings 20 in skirt 18. Suchdebris can be subsequently brushed away to place the device in conditionto drain during the next period of rain.

As shown in FIG. 4 drain cover 110 is provided with a smaller pattern ofopenings or apertures 117 on its top surface 112. It will be understoodthat any pattern of openings 117 can be provided without departing fromthe novel scope of the present invention. Such openings as slots, othershaped holes and others are well known in the art and some will bedemonstrated below and in conjunction with FIGS. 8, 9 and 11.

Referring now to FIGS. 5, 6 and 7, it will be seen that a drain cover 10is seated within pipe 32, which, as will be understood by persons havingordinary skill in the art, may be any type of drain pipe used to drainland or floor areas. Drain pipe 10 is a generally cylindrical pipehaving walls 34 and an interior surface 35 and comes up through surface30. Drain cover 10 rests on surface 30 at its bottom rim 26. It will beunderstood that the meeting of surface 30 and bottom rim 26 will notprovide a water tight seal and that water heading towards the drain canenter between surface 30 and rim 26. It will be seen that drain cover 10when inserted into drain pipe 32 is manufactured, in a preferredembodiment, such that legs 22 are adjacent to surface 35 and thatfriction elements 24 on legs 22 (FIGS. 1 and 6) touch surface 35 andform a frictional hold therewith; keeping drain cover 10 within drainpipe 34 until removal is desired.

When water 38, or other liquid, is present on surface 30 having drainpipe 32, water will generally proceed from the surface into the drainpipe. Water 38 and all loose material 40 carried thereon will freelyenter drain pipe 32 and be carried to the terminus (not shown) of drainpipe 32. By placing drain cover 10 in the opening of drain pipe 32 water38 and only small particles, having a size no greater than the size ofopenings 20, will be allowed to pass through the drain cover until thelevel of the water exceeds the height of drain cover skirt 18. Whendrain cover 10 is inserted within drain pipe 32, water will approachdrain cover 10 and when the water reaches the opening 20, it willproceed to drain pipe 32. If leaves 40 or other debris is carried by thewater to drain cover 10 openings 20 may be blocked, slowing the flow ofwater into drain pipe 32. When this occurs the surface of the water willcontinue to rise until it reaches opening 17 in the top surface 12 ofdrain cover 10 and then water 38 and leaves 40 and other debris willflow into drain pipe 32 through larger openings 17. In a preferredembodiment larger openings 17 have either an equivalent or greatersurface area, as shown in FIG. 1, as the opening of pipe 32 so as tocause no additional hindrance to the drainage of surface 30.

It will be understood by persons having ordinary skill in the art that adrain cover of the prior art, having a generally flat profile (at ornear the level of the surface to be drained) with openings thereon thatare of the type shown in skirt 18 of the present invention, whenpresented with a generally flat surface to drain and on which surfacelays debris such as leaves and the like, would clog in the presence ofwater (coming from a typical rain occurrence) allowing water to rise onthe surface and potentially causing damage to adjacent structures andother property due to flooding. In the present invention a two prongapproach to flooding is presented: a first fluid draining surface ispresented in a generally vertical configuration with a second fluid anddebris draining surface provided at a slight elevation on a generallyhorizontal configuration. When water is present alone or with very smallsized debris, the first fluid draining surface adequately drains thearea, and when larger debris is present and causes the first fluiddraining surface to clog, the second fluid draining surface allows forthe removal of water that could otherwise damage adjacent property.

The device of the present invention, when placed on a surface to bedrained, provides the same type of drainage control as a flat perforateddrain cover of the prior art, and, should clogging of the smallentryways occur, permits the flow of larger debris and water into thelarger opening in the elevated top surface. In this way, adjacentproperty, structures and items are given increased protection againstwater damage. The device, as described is made of structural materialsso that if stepped on or driven over by a vehicle the device will remainintact and the dimensions of the preferred embodiment are such that thedevice does not present too great an obstacle for either pedestrians orvehicles.

In a further embodiment of the device of the present invention, a draincover 210 is shown in FIGS. 8A, 8B, 8C and 11. It will be seen that thedrain cover 210 of FIG. 8 is generally of the type shown in FIG. 4 anddescribed above with like numbered elements having characteristics andfunctions as described for their counterparts above. Drain cover 210 isshown having a larger surface area 212 than that of correspondingportion of the device of FIG. 1. Further, as will be seen, theembodiments shown in FIGS. 8 and 11 further comprise a set of shutters250, 252 attached by a pivot 254 to device 210 at about the center 216 cof elements 216 (FIG. 11). It will be understood that shutters 250, 252can be attached in various manners by persons having ordinary skill inthe art without departing from the novel scope of the present invention.Shutters 250, 252 are placed so that they can pivot to close off largeopenings 217 such that if desired drain cover 210 can be utilized todrain fluids and smaller particles alone but not large debris. While theuse of such a system will close one half of the draining surface 217,having the other half open will generally permit larger debris to beaccepted within the pipe and thereby allow the drain to function in thepresence of debris. The user of such a device can close more of theportion of the top draining surface 217 such that more than 50% up to100% closure can be achieved as desired.

As illustrated, shutters 250, 252 are installed, in the preferredembodiment, under draining surface 217 so as to protect them from damageof a vehicle or persons traversing them. As drain cover 210 is generallya friction fit cover, the user may remove drain cover 210 from the drainpipe (32 in FIG. 5) adjust the shutters as desired and replace the coverin the drain opening. It will be understood that shutters 250, 252 couldbe closed or opened without removing drain cover 210 from the drainopening in various manners know to persons having ordinary skill in theart. In the use of drain cover 210, the user may adjust shutters 250,252 to provide sufficient drainage for the conditions present and canalso adjust the amount of drainage permitted by manipulation of theshutters. Should there be a requirement or other desire that largedebris not be allowed in a drain, the user can close off the openings217 fully and thereby comply with such requirements. In situations wherelarge debris has value the ability to close off the larger openings 217and thereby preserve the debris on the surface to be drained would befacilitated.

In another embodiment, a device 260 (FIG. 8A) is included and caninclude means to sense water flow and/or the presence of water or waterpressure on surface 217 and have further means to open and closeshutters 250, 252 as required to prevent flooding. It will be understoodthat device 260 can include remote sensing means or other means allowingthe user to open and close shutters 250, 252 as desired locally orremotely or automatically in response to programmed criteria; suchdevices as device 260 are well known and can be adopted to permit anymanner of functional, automated or remote control of the shutters tooptimize drainage. In addition, the device can include means to lower orraise the depending skirt relative to the surface 30 such that asdesired more or less flow of fluids and particles can be managed bymaking the device shorter or taller, respectively. The skirt 218 couldbe made to telescope into larger or smaller configurations, or a longerskirt can be made and placed lower into the drain opening and thenraised as needed. Such means to telescope or raise or lower the device260 could include manual, remote and automated means known to personshaving ordinary skill in the art. Further, the device 260 can includemeans to notify the owner or another person of the presence of damagingwater on the surface to be drained.

As shown in FIGS. 8A, 8B and 8C, respectively, the shutters can becompletely shut, providing no access to large debris or can be shut, bythe manipulation of one shutter with respect to the other, in variousdegrees between 50% open and completely shut. As illustrated, FIG. 8Bshows a 75% shut configuration and FIG. 8C shows the 50% shutconfiguration.

In a further embodiment, illustrated in FIG. 9, shutters 350, 352 areillustrated having additional openings thereon, such that when openeddrain cover 310 provides the same two level type of drainage describedherein and when closed there is provide drainage akin to a standarddrain having only small opening that block larger debris.

Although illustrative embodiments of the invention have been shown anddescribed, it is to be understood that various modifications andsubstitutions may be made by those skilled in the art without departingfrom the novel spirit and scope of the invention.

What is claimed is:
 1. A drain cover, for use on a drain opening in a generally flat surface, comprising: a plate having an aperture thereon, the aperture encompassing a desired amount of area of the surface of the plate, the plate having an edge about its perimeter; and a skirt attached to the edge of the plate and depending therefrom, the skirt having a lower edge, for placement adjacent the generally flat surface, and perforations therethrough, to permit the flow of liquids, such that the drain cover can be positioned to accept fluid through the plate aperture only when the perforations of its skirt are blocked and water rises above the skirt.
 2. The drain cover of claim 1, wherein the drain cover and aperture are of a sufficient size to accept large leaves through the aperture.
 3. The drain cover of claim 1, wherein the skirt has a length from the edge of the plate to the drainage surface of about ½ inch.
 4. The drain cover of claim 1, wherein the skirt has a length from the edge of the plate to the drainage surface of about ¾ inch.
 5. The drain cover of claim 1, wherein the plate comprises a generally circular area and the skirt depends from the circumference thereof.
 6. The drain cover of claim 5, wherein the plate comprises structural material formed as an “X” within the circumference of the skirt.
 7. The drain cover of claim 1, including at least one leg, attached to the plate, depending therefrom for insertion into a drain pipe.
 8. The drain cover of claim 7, wherein the at least one leg comprises a friction element for removable contact with the drain pipe.
 9. The drain cover of claim 7, wherein the at least one leg is four legs.
 10. The drain cover of claim 1, further comprising a shutter to close the aperture.
 11. The drain cover of claim 10, wherein the shutter is movable so as to adjust the size of the aperture.
 12. A drain cover, for use on a generally flat open drainage surface, comprising: a generally cylindrical plate having an aperture thereon, the aperture opening in an area of the plate comprising at least 50% of the surface of the plate, the plate having an edge about its circumference; and a perforated skirt attached to the plate and depending from the circumference of the plate, the skirt having a lower edge for placement adjacent the drainage surface such that the generally cylindrical plate is positioned to accept fluid through its aperture only when the perforations of the skirt are either clogged or otherwise insufficient to drain water and water rises above the skirt.
 13. The drain cover of claim 12, wherein the drain cover and aperture are of a sufficient size to accept large leaves through the aperture.
 14. The drain cover of claim 12, wherein the skirt has a length from the edge of the plate to the drainage surface of about ½ inch.
 15. The drain cover of claim 12, wherein the skirt has a length from the edge of the plate to the drainage surface of about ¾ inch.
 16. The drain cover of claim 12, including at least one leg, attached to the plate, depending therefrom for insertion into a drain pipe.
 17. The drain cover of claim 16, wherein the at least one leg comprises a friction element for removable contact with the drain pipe.
 18. The drain cover of claim 12, further comprising a shutter to close the aperture.
 19. The drain cover of claim 18, wherein the shutter is movable so as to adjust the size of the aperture.
 20. The drain cover of claim 19, including means to determine the optimal aperture opening and to adjust the aperture accordingly. 